Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
  • D04H1/559—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving the fibres being within layered webs
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F13/00—Bandages or dressings; Absorbent pads
  • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
  • A61F13/36—Surgical swabs, e.g. for absorbency or packing body cavities during surgery
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
  • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
  • A61L15/22—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing macromolecular materials
  • A61L15/28—Polysaccharides or their derivatives
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4266—Natural fibres not provided for in group D04H1/425
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4374—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece using different kinds of webs, e.g. by layering webs
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/44—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling
  • D04H1/46—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/44—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling
  • D04H1/52—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling by applying or inserting filamentary binding elements
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
  • D04H1/74—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being orientated, e.g. in parallel (anisotropic fleeces)
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F13/00—Bandages or dressings; Absorbent pads
  • A61F2013/00361—Plasters
  • A61F2013/00365—Plasters use
  • A61F2013/00463—Plasters use haemostatic
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F13/00—Bandages or dressings; Absorbent pads
  • A61F2013/00361—Plasters
  • A61F2013/00365—Plasters use
  • A61F2013/00519—Plasters use for treating burn
  • A61F2013/00523—Plasters use for treating burn with hydrogel
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2400/00—Materials characterised by their function or physical properties
  • A61L2400/04—Materials for stopping bleeding

Definitions

• the present invention relates to an alginate fabric. More particularly, the invention concerns a wound dressing or surgical haemostat formed from a non- woven fabric of alginate fibres which has high absorbency and good integrity and to a process for the preparation of such a fabric.
• Alginate fibres have been known for some time as being useful in the preparation of surgical dressings. For example, United Kingdom Patent No. 653341, published in 1951, describes surgical dressings formed from fibres of calcium alginate.
• Various types of dressing formed from fabrics comprising alginate fibres are known. For example, a surgical dressing comprising a carded web of layered alginate fibres is known; and Kaltostat haemostatic wound dressing is a carded and needle-tacked web of alginate fibres.
• the ideal dressing will be haemostatic and will have good structural integrity, high absorbency and a high liquid retention capacity. Good integrity is particularly important for a dressing for use in surgery since it must be possible to lift the whole dressing away from the wound when saturated in blood.
• High absorbency means that an efficient uptake of exudate or blood, together with its associated toxins and other undesirable matter, can be achieved.
• a high liquid retention capacity means that blood is retained within the dressing when it is removed from the wound and dripping of blood is minimised.
• gauze dressings currently used in surgery are not haemostatic, that is to say, they do not inhibit bleeding.
• Presently available haemostatic alginate dressings are not suitable for use in surgery because they have insufficient structural integrity such that they tend to disintegrate.
• EP-A-0344913 describes an alginate wound dressing of an integrity alleged to be such as to enable it to be lifted in one piece from a wound even when saturated with blood or other saline fluids.
• the wound dressing provided by EP-A-0344913 comprises a non-woven fabric of alginate staple fibres, the fabric being substantially free from any adhesive binder or of interfusing of fibres at their crossing points.
• the required integrity is imparted to the dressing fabric of EP-A-0344913 by subjecting the non-woven web of staple alginate fibres to a hydraulic entanglement procedure which preferably comprises hydroentanglement.
• United States Patent no. 3,937,223 discloses a haemostatic surgical felt comprising fibres of a polymer having glycolic acid ester linkages and which is completely absorbed when enclosed in living tissue. The felt has partially compressed heat embossed surfaces.
• United States Patent no. 4,128,612 (divided from above-mentioned US 3,937,223) relates to a process for the manufacture of a haemostatic surgical felt having a textured and embossed surface. Briefly, the process includes the steps of randomly air laying fibres of a living tissue absorbable polymer into a mat and heating and compressing the mat so as to emboss it. US Patent no. 4,128,612 stresses the random formation of the mat and suggests that orientation of the fibres is to be avoided. There is no indication that the process described in the US Patent no. 4,128,612 could be applied to alginate fibres or that a layered mat of fibres could be used. We have now found that dressings can be prepared from alginate fibres which fulfill the abovementioned criteria for a surgical haemostat.
• the requisite good structural integrity can be imparted to the alginate dressing by firmly joining together layers of alginate material at a plurality of points to produce a composite fabric. This may be achieved, for example, by stitching, or, preferably, by calendering. We have surprisingly found that by embossing regions of the layered alginate fabric, for example, by stitching or calendering, a haemostatic material having good integrity is produced without substantially affecting the absorbency or liquid retention properties of the fabric.
• the present invention accordingly provides a non-woven fabric suitable for use as a surgical haemostat comprising layers of alginate staple fibres, which layers are joined together at a plurality of points throughout the fabric whereby an embossed pattern is produced on at least one of the major external surfaces of the fabric. It is necessary that the embossed areas of the fabric should be of sufficient extent to impart integrity, but should not be so extensive that the absorbency of the finished fabric is adversely affected. Suitable ratios for embossed:unembossed area are in a range of 1:1 to 1:9. Preferably the ratio of embossed:unembossed area will be in the region of 1:4.
• the present invention provides a non-woven fabric suitable for use as a surgical haemostat comprising layers of alginate staple fibres which layers are joined together at a plurality of points throughout the fabric whereby an embossed pattern is produced on at least one of the major external surfaces of the fabric wherein the ratio of embossed:unembossed area is in the range of 1:1 to 1:9.
• the present invention further provides a non- woven fabric suitable for use as a surgical haemostat comprising layers of alginate staple fibres, which layers are joined together at a plurality of points throughout the fabric by stitching or calendering whereby an embossed pattern is produced on at least one of the major external surfaces of the fabric.
• the present invention provides a calendered, non-woven, fabric comprising layers of alginate staple fibres which fabric bears an embossed pattern on at least one of its major external surfaces.
• both of the major external surfaces of the fabric according to the invention will bear an embossed pattern.
• the haemostatic action of alginates is believed to be related to calcium ion release.
• calcium ions are released and exchanged for sodium ions.
• Calcium ions interact with the blood clotting cascade mechanism, resulting in clot formation.
• the degree of calcium ion release can be controlled by selecting an appropriate alginate source material and/or by treating the alginate so as to enhance its calcium ion release properties.
• Suitable alginates for use in the invention include both water-soluble and water-insoluble alginates, but will preferably be water-insoluble alginates.
• a particular water-insoluble alginate for use in the invention is calcium alginate. Nevertheless, the calcium alginate may advantageously contain up to 1.5% by weight of sodium ions. Preferably 99% calcium alginate fibres will be used.
• Alginic acid is a linear polymer comprising D- mannuronic acid and L-guluronic acid, the relative proportions of which vary with botanical source and state of maturation of the source plant. Alginates which comprise a high proportion of guluronic acid are known as high G alginates, and alginates which comprise a low proportion of guluronic acid are known as low G alginates.
• Both high G alginates and low G alginates are suitable for use in the present invention.
• High G alginates chelate calcium more strongly than do low G alginates.
• a low G alginate may be selected.
• a high G alginate may be preferred.
• High G alginate may be obtained from, for example, laminaria hyperborea, and is commercially available as, for example, LF 10/60 from Protan Ltd.
• Low G alginate may be obtained from, for example, ascophyllum nodosu f and is commercially available as, for example, Lamitex (Protan Ltd.) and Manucol DM (Kelco) .
• a particularly suitable oxidising agent for this purpose is hypochlorite ion.
• the present invention provides a method of enhancing calcium ion release from alginate material which comprises treating the material with an oxidising agent.
• X-ray detectable material may be incorporated into the dressing for this purpose.
• the invention further provides a non-woven fabric suitable for use as a surgical haemostat comprising layers of alginate staple fibres, which layers are joined together at a plurality of points throughout the fabric whereby an embossed pattern is produced on at least one of the major external surfaces of the fabric, and containing X-ray detectable material.
• X-Ray detectable material for use in the fabrics of the present invention may take the form of, for example, yarn, ribbon, tape or strip. It is important that the X-ray detectable material is soft and pliable.
• X-Ray opaque materials include, for example, barium sulphate, tungsten and bismuth.
• carrier materials for the X-ray opaque material are commercially available, including PVC, polyurethane (PU) and silicon.
• the preferred X-ray detectable material for use in the present invention is one or more PVC X-ray detectable strips containing barium sulphate.
• the X-ray detectable material may be at least partially bound to the alginate fabric.
• the carrier material comprises a thermally fusable material, such as a plastic, for example PVC or PU
• bonding of the X-ray detectable material to the alginate fabric may be achieved by partially melting the carrier material before or during insertion of the X-ray detectable material into the fabric, or, preferably, during the embossing process.
• Calendering is a process whereby a web of material is compressed, usually between heated rollers.
• At least one the rollers of the calender must have a textured surface.
• one or both rollers may have a plurality of either engravings or, preferably, raised portions. Conveniently, only one of the rollers has a textured surface.
• an embossed pattern may be produced on both major external surfaces of the finished fabric. This is because the pressure of the textured roller on the surface of the fabric it contacts tends to cause a reverse or "negative” of the embossed pattern produced on that surface to be produced on the opposite major external surface of the fabric. This "negative" pattern is considerably less pronounced than the pattern produced by direct embossment.
• the quality of the embossed pattern is dependent on the temperature, pressure and speed of the rollers during the calendering process. If the pattern is not firmly embossed the calendered regions of the fabric tend to revert and in a relatively short time the embossed effect is lost.
• a roller speed of 1 to 40 metres per minute, preferably 1 to 10 metres per minute, more preferably 3 metres per minute at a temperature of about 80°C to about 210°C, preferably 130°C and a pressure of 1 ton to 15 tons, preferably approximately 6 tons.
• the wind up tension should be kept to a minimum. Over tensioning the web as it is wound up will tend to stretch the material as it leaves the calender nip. This results in reduced absorbency of the final product.
• the present invention therefore provides a process for the preparation of an alginate fabric of good absorbency and high structural integrity which comprises calendering regions of a web of non-woven layered alginate fibres so as to produce an embossed pattern on at least one major external surface of the web.
• the calendering process will be conducted at a temperature of from 80°C to 210°C and a pressure of from 1 ton to 15 tons.
• the web of non-woven layered alginate fibres is produced by cross-lapping.
• Cross- lapping is a process whereby a web is built up by the sequential laying of layers of fibres one on another until a web of the desired weight is achieved.
• the present invention provides a process for incorporation of one or more X-ray detectable strips into an alginate fabric which process comprises the steps of:
• the fabric prepared by the process according to the invention typically has absorbency in the region of 10.5 times its own weight and a water-retention capacity in the region of 9.5 times its own weight. This compares with absorbency in the region of 6.5 times its own weight and a water-retention capacity in the region of 6.5 times its own weight for conventional surgical gauze.
• the fabric according to the present invention is particularly suitable for use as a surgical haemostat, it will be appreciated that it can also advantageously be employed as a wound dressing for non- surgical applications.
• the fabric according to the present invention is also particularly suitable for use in dentistry.
• the alginate fabric according to the invention can suitably be manufactured in a range of basis weights, typically from about 120g/m 2 to about 360g/m 2 , preferably from about 160g/m 2 to about 240g/m 2 , more preferably, about 180g/m 2 .
• the basis weight of a given fabric will generally be dependent upon the use, for example as a wound dressing or surgical haemostat, to which the fabric is to be put.
• a basis weight in the region of 120g/m 2 is indicated for a moderately exuding wound whereas a basis weight in the region of 280g/m 2 is indicated for a heavily exuding or freely bleeding wound.
• the present invention provides a wound dressing or surgical haemostat comprising a non-woven fabric comprising layers of alginate staple fibres which layers are joined together at a plurality of points throughout the fabric whereby an embossed pattern is produced, optionally containing X-ray detectable material.
• the present invention provides a method of treating a mammalian subject undergoing surgery, which method comprises applying to the site of surgery a surgical haemostat according to the present invention.
• the present invention provides a method of treating a mammalian subject having a wound, which method comprises applying to the wound a wound dressing according to the present invention.
• wound includes cut, sore, ulcer, blister, burn, rash or any other lesion or area of troubled skin.
• the wound dressings or surgical haemostats formed from the alginate fabric according to the present invention will advantageously be conventional dressings well known in the art.
• suitable dressings include bandages, adhesive strip dressings, island dressings, pads of various kinds, surgical sponges and packs, ward dressings, and such articles as tampons which may, for example, be impregnated with an antifungal agent such as miconazole for the treatment of candidal vaginitis (vaginal thrush) .
• Such dressings may conveniently be prepared by standard methods known from the art.
• the dressings in accordance with the present invention will conveniently be packaged in a hermetically-sealed envelope and sterilised, e.g. with ethylene oxide or by gamma-irradiation.
• Calcium alginate fibre was prepared as described in Preparation 1 of WO-A-89/12471, crimped, staple cut and converted to non-woven fabric by a conventional carding, cross-lapping and needle punching technique.
• the calender is heated to 130°C.
• Web (basis weight 180g/m 2 ) is loaded to the feed roller.
• a core is loaded to the wind up and locked in position.
• the web is laid on the top surface of the fabric leader and the X- ray detectable strip aligned with the grooves in the calender.
• the material is passed through the calender nip and collected on the wind up roller.
• TEST METHOD The apparatus used in the determination of absorbency is depicted in Fig. 1, and consists of water bath 1 containing a 0.9% (w/w) aqueous saline solution, absorbent strip 2, burette 3, top-pan balance 4 and overflow 5.
• the thickness of the absorbent strip 2 is substantially equivalent to that of the dressing 7.
• the filter paper 8 has substantially the same planar dimensions as the dressing 7 but not necessarily the same thickness.
• the apparatus is set up with the surface 6 of the saline solution level with the top surface of the top-pan balance 4.
• the flow of liquid from the burette 3 is then adjusted to approximately 1.5 ml per minute.
• the absorbent strip 2 is then saturated and placed between the bath 1 and the balance 4, as depicted in Fig. 1.
• the balance 4 is then tared.
• a weighed dressing 7 and filter paper 8 (cut to size) is positioned as depicted in Fig.l. After six minutes the weight shown on the balance 4 is recorded.
• the dressing 7 and filter paper 8 are then removed and any residual weight on the balance 4 noted.
• the average absorbency of the alginate fabric of Example I is 10.56g of saline per gram of dressing; whereas, from Table II, the average absorbency of commercial surgical gauze (4 layers) can be calculated to be 6.42g of saline per gram of dressing.
• the average retention capacity of the alginate fabric of Example I is 9.48g of serum per gram of dressing; whereas, from Table IV, the average retention capacity of commercial surgical gauze can be calculated to be 6.4g of serum per gram of dressing.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mechanical Engineering (AREA)
• Veterinary Medicine (AREA)
• Epidemiology (AREA)
• Public Health (AREA)
• General Health & Medical Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• Surgery (AREA)
• Vascular Medicine (AREA)
• Heart & Thoracic Surgery (AREA)
• Biomedical Technology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Hematology (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Materials For Medical Uses (AREA)
• Nonwoven Fabrics (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10694248

Family Applications (1)

Country Status (13)

Cited By (7)

Families Citing this family (3)

Citations (9)

• 1991
  • 1991-05-01 GB GB919109367A patent/GB9109367D0/en active Pending
• 1992
  • 1992-04-30 WO PCT/GB1992/000792 patent/WO1992019802A1/en not_active Application Discontinuation
  • 1992-04-30 ES ES92908962T patent/ES2094909T3/es not_active Expired - Lifetime
  • 1992-04-30 DE DE69215513T patent/DE69215513T2/de not_active Revoked
  • 1992-04-30 CA CA002109217A patent/CA2109217A1/en not_active Abandoned
  • 1992-04-30 EP EP92908962A patent/EP0583276B1/en not_active Revoked
  • 1992-04-30 KR KR1019930703294A patent/KR100226567B1/ko not_active IP Right Cessation
  • 1992-04-30 AU AU16601/92A patent/AU663316B2/en not_active Ceased
  • 1992-04-30 AT AT92908962T patent/ATE145679T1/de active
  • 1992-04-30 DK DK92908962.1T patent/DK0583276T3/da active
  • 1992-04-30 JP JP04508648A patent/JP3037754B2/ja not_active Expired - Fee Related
  • 1992-07-01 IE IE921402A patent/IE79239B1/en not_active IP Right Cessation
• 1997
  • 1997-02-27 GR GR970400386T patent/GR3022700T3/el unknown

Patent Citations (9)

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